107 results about "Bone prosthesis" patented technology

An ankle joint replacement prosthesis comprises a tibia prosthesis assembly and a talus prosthesis, the tibia prosthesis assembly comprises a tibia prosthesis body and a cushion block, the tibia prosthesis body and the cushion block are in an arc shape with the middle bent upwards on the sagittal plane, the cushion block is arranged at the bottom of the tibia prosthesis body in a sleeving mode, and the surface of the upper portion of the tibia prosthesis body is a tibia joint face. The surface of the lower portion of the cushion block is a first articular surface, the surface of the upper portion of the talus prosthesis is a second articular surface, the second articular surface is in an arc shape with the middle bent upwards on a sagittal plane, the surface of the lower portion of the talus prosthesis is a talus joint surface, and the first articular surface is matched with the second articular surface. When the prosthesis is implanted, only the articular cartilage and the subchondral bone need to be treated at the far end of the tibia, so that the bone at the far end of the tibia is reserved to the maximum extent, the anatomical integrity of the bone is guaranteed, the stability of the prosthesis is enhanced, the service life is prolonged, and the clinical operation effect is improved.

According to one example, a tibial prosthesis that can include a tibial bearing component, tibial baseplate, an insert and a fastener. The tibial bearing component can have medial and lateral proximal articular surfaces and an opposing distal surface. The tibial bearing component can define at least one recess therein with the recess having an opening at a periphery of the tibial bearing component. The tibial baseplate can be coupled to the tibial bearing component on the proximal surface thereof and having a distal surface configured to be disposed on a resected proximal surface of a tibia. The insert can be configured to be disposed within the recess and can engage the tibial baseplate and the tibial bearing component. The fastener can be insertable into the tibial bearing component and can be configured to retain the insert to the tibial baseplate.

The utility model provides a multi-curvature ankle joint prosthesis which comprises a tibia prosthesis connected with a tibia, a talus prosthesis connected with a talus and a cushion block with one side connected with the tibia prosthesis, a joint contact surface is arranged on the other side of the cushion block, and a talus contact surface matched with the joint contact surface is arranged on one side of the talus prosthesis. The curvature of the sagittal plane Z in the talus contact face is reduced from front to back, and the instantaneous rotation center of the talus prosthesis on the joint contact face is in an arc shape. According to the multi-curvature ankle joint prosthesis, the talus contact face and the anatomical structure of the human body are high in consistency, the natural form and the motion mode of the ankle joint are accurately restored, the ankle joint prosthesis better conforms to biomechanics and kinematics in the motion process, the motion stability of the human body is improved, local friction stress of the ankle joint prosthesis is smaller, and the ankle joint prosthesis is more stable in motion. And the service life of the ankle joint prosthesis is prolonged, so that the durability of the ankle joint prosthesis is improved.

The ankle joint prosthesis comprises a tibia prosthesis and a talus prosthesis, the tibia prosthesis is provided with a keel, the keel is used for being implanted into a tibia and extends in the front-back direction of the tibia prosthesis, the talus prosthesis is arranged on the lower side of the tibia prosthesis, the talus prosthesis is provided with a fixing rod, and the fixing rod is arranged on the lower side of the tibia prosthesis. The fixing rod is used for being implanted into the talus and obliquely extends downwards from front to back, an included angle alpha is formed between the extending direction of the keel and the extending direction of the fixing rod, and alpha is larger than or equal to 10 degrees and smaller than or equal to 85 degrees. The ankle joint prosthesis is reasonable in structural design, the stability of the ankle joint prosthesis in the human body movement process can be enhanced, and the dislocation risk of the prosthesis is reduced.

The invention provides a tibial prosthesis which comprises a tibial platform provided with a containing groove and a communicating groove, the containing groove is communicated with the upper surface of the tibial platform, and the communicating groove is communicated with the groove bottom wall of the containing groove and the lower surface of the tibial platform; the gasket structure is arranged in the containing groove in a floating mode in the vertical direction; the bone growth body is connected to the lower portion of the gasket structure and located in the communicating groove, and the gasket structure can drive the bone growth body to penetrate out of the tibial plateau downwards when floating in the vertical direction. According to the technical scheme, the problem that in the prior art, the time needed for combining the sclerotin and the prosthesis of a patient is long can be effectively solved.

A tibia prosthesis comprises a tibia gasket, a platform support and a pushing part. A first fixing block connected with the femoral condyle is arranged on the upper portion of the gasket, a first opening is formed in the middle of the gasket, and second fixing blocks are arranged in three surrounding second openings. A third opening is formed in the first groove in the side face of the gasket, and a first limiting block with a fifth opening is arranged in a fourth opening in the bottom. A spring in the third opening pushes the second limiting block to be clamped into the fifth opening. The platform support is provided with a sixth opening and a second groove, a fourth limiting block capable of being opened is arranged in a seventh opening in the upper portion, and a fifth limiting block is hinged into the second groove. A pushing part is arranged in a lower shell of the platform support and comprises a hexagon screw and a fixing ring, a ninth opening is formed in the screw, and the fixing ring is connected with the rotating part through a ratchet wheel. And during rotation, the rotating part pushes the first limiting block to enter the seventh opening, the fourth limiting block is retracted and limited after being opened, and meanwhile, the second limiting block is clamped into the fifth opening to be fixed. And the second fixing block is clamped into the ninth opening to connect the screw and the gasket. And when the rotating part enters the second groove, the fifth limiting block is pushed to be clamped into the second groove, and overall fixing is completed.

The invention discloses a tibia prosthesis posture determination method and device, a storage medium and electronic equipment. The method relates to the technical field of medical treatment and comprises the steps that a theoretical rotation axis is determined according to a skeleton three-dimensional model of a target object, and the theoretical rotation axis is determined based on a posterior condylar line in the skeleton three-dimensional model; acquiring a pose transformation set of the knee joint of the target object from a straight position to a flexion position, and performing fitting according to the pose transformation set to obtain a fitting rotation axis; and determining target pose information of the tibial prosthesis according to the fitting rotation axis and the theoretical rotation axis. Through the method and the device, the problem that the accuracy of determining the pose information of the tibial prosthesis is relatively low due to the fact that the pose information of the tibial prosthesis is planned based on artificial experience in related technologies is solved.

The invention relates to the technical field of medical instruments, in particular to a hip joint thighbone prosthesis and a hip joint thighbone prosthesis manufacturing method. The hip joint femoral prosthesis comprises a spherical prosthesis main body and a connecting part, the spherical prosthesis main body is provided with an opening, one end of the connecting part extends into the spherical prosthesis main body and is connected with the spherical prosthesis main body, and the other end of the connecting part extends out of the opening; wherein the inner wall of the spherical prosthesis main body is provided with a functional gradient porous structure, and the porosity and the pore diameter of the functional gradient porous structure are gradually increased from the inner wall of the spherical prosthesis main body to the center direction of the spherical prosthesis main body in the preset direction. According to the hip joint thighbone prosthesis, the service life of a surface replacement type hip joint thighbone prosthesis can be prolonged, the problem that an existing biological fixation type prosthesis is loosened and loses efficacy due to stress shielding is solved, and the risk that a porous structure is prone to falling off from a base body in a long-term load environment is reduced.

Embodiments of the present invention provide a patellar prosthesis and a total knee joint prosthesis. In this embodiment of the invention, the patellar prosthesis is used to cooperate with a femoral prosthesis. The femoral prosthesis includes a medial condyle, a lateral condyle, and an intercondylar fossa for corresponding cooperation with the tibia. The medial and lateral condyles have a recessed groove in the middle to form a trochlear groove for receiving the patellar prosthesis. The width of the intercondylar fossa is L7. The patellar prosthesis includes a patellar articular surface that cooperates with the femoral articular surface. When the human body is flexed greater than 90°, the patellar prosthesis cooperates with the intercondylar fossa. The width of the overlap between the patellar prosthesis and the lateral condyle is L6, and the width of the overlap between the patellar prosthesis and the medial condyle is L5. When the human body is flexed between 90° and 135°, L5 / L7 is 0.11 to 1.30, and L6 / L7 is 0.11 to 1.42. Therefore, the patellar prosthesis according to embodiments of the present invention has the advantage of improving the stability of the patellar joint.

The customized artificial meniscus prosthesis comprises a meniscus body, a joint cotyle is arranged in the middle of the meniscus body, a meniscus joint protrusion capable of simulating the shape and the movement track of a meniscus is installed in the joint cotyle, and a center nail is fixedly connected to the top of the meniscus joint protrusion. The free end of the center nail extends out of the lunar bone body and is arranged in a head-shaped bone of the wrist of the human body, and a plurality of sets of ligament suture holes are further formed in the back side of the lunar bone body. The customized artificial lunar bone prosthesis provided by the invention aims to be applied to lunar bone replacement surgery, mainly aims at treating advanced lunar bone ischemic necrosis caused by non-traumatic or traumatic factors, and is beneficial to improving the stability of the prosthesis and improving the joint activity; basic biomechanics and clinical experiment research verify that the prosthesis has good mechanical properties and clinical curative effects, promote development of the lunar bone prosthesis, enable more patients to retain wrist joint movement, create more values for society and families, and contribute to achieving the goal of healthy China.

The application provides a tibial prosthesis, which comprises: a tibial platform comprising a base plate and a mounting table arranged on the lower surface of the base plate; an extension rod comprising a rod body and a cone table arranged on the upper end of the rod body, the mounting table is provided with a tapered hole, the cone table is arranged in the tapered hole and matched with the tapered surface of the tapered hole, the cross-sectional size of the tapered hole and the cross-sectional size of the cone table are gradually reduced in the upward direction; a ring-shaped prosthesis is arranged outside the mounting table and the extension rod, the ring-shaped prosthesis and the extension rod are screw-threaded, when the ring-shaped prosthesis rotates forward relative to the extension rod, the ring-shaped prosthesis moves upward relative to the extension rod, and the upper end of the ring-shaped prosthesis can abut against the base plate; a locking structure can limit the reverse rotation of the ring-shaped prosthesis relative to the extension rod when the upper end of the ring-shaped prosthesis abuts against the base plate. Through the technical scheme provided in the application, the problem of poor stability of the tibial prosthesis in the related art can be solved.

The present invention discloses a method for calculating the physiological parameters of a model in hip prosthesis planning and an electronic device. The method includes obtaining a pelvic model, a left femoral model, a right femoral model, a first feature point set, a second feature point set, a third feature point set, a pelvic prosthesis model, and a femoral prosthesis model; determining a pelvic-pelvic prosthesis assembly model and a femoral-femoral prosthesis assembly model; updating the first feature point set and the target feature point set; splicing the pelvic-pelvic prosthesis assembly model, the femoral-femoral prosthesis assembly model, and the second femoral model according to a first splicing method and a second splicing method, respectively, and calculating the hip joint offset and the hip joint length based on the coordinates of the feature points in the second feature point set and the third feature point set, respectively. The present application calculates the hip joint offset and the hip joint length based on the feature points in the second feature point set and the third feature point set, respectively, and can accurately obtain the numerical values ​​of the postoperative hip joint physiological parameters through the preoperative planned model.

According to one example, a femoral prosthesis system is provided that has a plurality of sizing options using two families of femoral prostheses is disclosed. The second family of femoral prostheses can have a predetermined increase in femoral posterior condylar offset relative to the first family of femoral prosthesis. In one example, the second family of femoral prostheses can have the predetermined increase in the femoral posterior condylar offset while maintaining substantially a same femoral medial-lateral condylar extent relative to a comparably sized one of the first family of femoral prostheses.

The application provides a bionic total ankle joint replacement prosthesis, and belongs to the technical field of medical devices. The bionic total ankle joint replacement prosthesis comprises a talus prosthesis, a tibia prosthesis and a sliding liner arranged between the talus prosthesis and the tibia prosthesis, and the tibia prosthesis is provided with a second reinforcing component fixed with the tibia and the sliding liner. The top of the tibia prosthesis is provided with a curved groove. The top of the talus prosthesis is movably connected with the bottom of the sliding liner, and the talus prosthesis is fixed on the talus. The bionic total ankle joint replacement prosthesis simulates the natural structure of the human ankle joint, helps to restore the normal movement function of the joint, makes the joint movement more flexible and natural, forms multidirectional movement in front and back, left and right and other directions, realizes the functions of varus, valgus, internal rotation, external rotation and movement in other directions of the whole bionic total ankle joint replacement prosthesis, improves the movement range of the whole bionic total ankle joint replacement prosthesis, forms multidirectional bionic functions, and meets the diversified needs of patients in daily life.

This application provides a knee femoral prosthesis. The knee femoral prosthesis includes: an anterior portion configured for fitting onto the distal anterior condylar osteotomy surface of the femur; a posterior portion configured for fitting onto the distal posterior condylar osteotomy surface of the femur; a middle portion configured to connect the anterior and posterior portions; and at least two through-holes configured to receive fasteners to secure the knee femoral prosthesis to the distal femur. The at least two through-holes include through-holes whose bore axes intersect or are opposite to each other. Using the knee femoral prosthesis according to this application, a more targeted prosthesis fixation strategy can be provided based on the patient's individual condition, thereby achieving better initial prosthesis stability. Furthermore, this application also relates to a knee prosthesis system incorporating this prosthesis.

The present application relates to the technical field of prosthesis mechanics analysis, in particular to a kind of talus prosthesis stability and stress distribution biomechanics analysis system, by three-dimensional modeling module, finite element analysis module, stability analysis module and report generation module composition;Three-dimensional modeling module processes CT data by reverse engineering technology;The three-dimensional model of talus prosthesis is constructed;Finite element analysis module is used to simulate the stress condition of talus prosthesis in different positions and different thickness cartilage cover;Stability analysis module is used to analyze the stress distribution of talus prosthesis in different positions by finite element calculation after ligament is successively cut off;Report generation module is used to generate stress distribution nephogram, and the stress distribution of talus prosthesis surface is shown.The present application establishes the model of talus prosthesis, predicts stress distribution and identifies potential failure point or excessive wear based on finite element analysis, to guide design improvement and material selection.

A tibial prosthesis comprises a tibial pad, a platform holder and a pushing part. The upper part of the pad has a first fixing block connected with femoral condyle, the middle part has a first opening, and the periphery has three second openings with second fixing blocks. The first recess has a third opening, and the bottom has a fourth opening with a first limiting block with a fifth opening. The spring in the third opening pushes the second limiting block to be clamped in the fifth opening. The platform holder has a sixth opening and a second recess, the upper part has a seventh opening with a fourth limiting block that can be expanded, and the second recess has a fifth limiting block that is hinged. The pushing part is set in the lower part of the platform holder, which comprises a hexagonal screw and a fixing ring, the screw has a ninth opening, and the fixing ring is connected with the rotating part through a ratchet. When rotating, the rotating part pushes the first limiting block into the seventh opening, expands the fourth limiting block, and then shrinks the limiting block, while the second limiting block is clamped in the fifth opening to be fixed. The second fixing block is clamped in the ninth opening to connect the screw with the pad. When the rotating part enters the second recess, it pushes the fifth limiting block to be clamped in the recess, and the overall fixation is completed.

This invention belongs to the field of foot and ankle joint replacement implant technology, and discloses an ankle joint talus prosthesis with an antibacterial porous interface and its preparation method. It includes a prosthesis substrate with an overall anatomically contoured structure, including a superior articular surface, a inferior articular surface, and an anterior articular surface; the area of ​​the prosthesis substrate in contact with residual bone tissue is designed as a three-dimensional porous structure; an antibacterial bioactive composite coating is grown in situ on the surface of the prosthesis substrate; it includes calcium and phosphorus bioactive components and antibacterial ions. This invention, by constructing an antibacterial bioactive composite coating at a porous bone integration interface, utilizes biocompatibility and osteoconductivity to induce bone tissue growth. Furthermore, the antibacterial ions can be slowly and continuously released in the interstitial spaces, achieving a dual function of promoting bone integration and preventing infection. Moreover, the antibacterial bioactive composite coating is formed through in-situ growth, resulting in a strong bond with the substrate and preventing detachment.

The utility model discloses a customized artificial lunar bone prosthesis which comprises a lunar bone body, a joint cotyle is arranged in the middle of the lunar bone body, a head-moon joint protrusion capable of simulating the form and the movement track of a head-moon bone is installed in the joint cotyle, and the top of the head-moon joint protrusion is fixedly connected with a center nail. The free end of the center nail extends out of the lunar bone body and is arranged in a head-shaped bone of the wrist of the human body, and a plurality of sets of ligament suture holes are further formed in the back side of the lunar bone body. The customized artificial lunar bone prosthesis provided by the utility model aims to be applied to lunar bone replacement surgery, mainly aims to treat advanced lunar bone ischemic necrosis caused by non-traumatic or traumatic factors, and is beneficial to improving the stability of the prosthesis and improving the joint movement; basic biomechanics and clinical experiment research verify that the prosthesis has good mechanical properties and clinical curative effects, promote development of the lunar bone prosthesis, enable more patients to retain wrist joint movement, create more values for society and families, and contribute to achieving the goal of healthy China.

The invention provides a sacrum prosthesis which comprises a main body part used for being connected with a sacrum or a vertebral body; the first connecting block is used for being connected with a first hip bone and is spaced from the main body part; the second connecting block is connected between the main body part and the second hip bone, and the second connecting block is adjustably arranged around the horizontal axis relative to the main body part; the fixing piece is connected between the main body part and the second connecting block; the first rotation stopping part is arranged on the main body part; and the second rotation stopping part is arranged on the second connecting block, and the second rotation stopping part can be in rotation stopping fit with the first rotation stopping part. According to the technical scheme, the problem that the sacrum prosthesis is difficult to adapt to different patients in the prior art is effectively solved.

The invention provides a magnesium alloy-hydroxyapatite composite bone prosthesis and a preparation method thereof.The preparation method of the magnesium alloy-hydroxyapatite composite bone prosthesis comprises the following steps that a target bone is scanned through CT, and a three-dimensional model containing an appearance structure and an internal structure is obtained; simplifying the appearance structure of the bone prosthesis, simulating an internal porous structure of the bone prosthesis, and designing a three-dimensional structure of the bone prosthesis; preparing hydroxyapatite printing slurry; printing a hydroxyapatite bracket by using a three-dimensional photocuring technology; carrying out cleaning, degreasing and high-temperature sintering on the hydroxyapatite scaffold; injecting molten magnesium alloy into the hydroxyapatite stent by using a pressureless permeation technology; and removing redundant materials by adopting a cutting tool, and grinding and polishing to obtain the magnesium alloy-hydroxyapatite composite bone prosthesis. The prepared magnesium alloy-hydroxyapatite composite auditory ossicle prosthesis has the advantages of being stable in positioning, not prone to shifting and disengaging, high in sound conduction efficiency, controllable in cost and capable of achieving personalized customization.

The utility model discloses a tibial prosthesis intramedullary positioning system which comprises a tibial plateau prosthesis, an eccentric adjusting component and an intramedullary rod. The tibial plateau prosthesis comprises a plateau part and a stand column, the eccentric adjusting component comprises a first connecting part and a main body part, the first connecting part is arranged at the upper end of the main body part, the central axis of the first connecting part and the central axis of the main body part are parallel and spaced, and the first connecting part is coaxially pivoted to the stand column; the intramedullary rod comprises a second connecting part and a rod part, the second connecting part is arranged at the upper end of the rod part, the central axis of the second connecting part and the central axis of the rod part are parallel and spaced, and the second connecting part is coaxially pivoted to the main body part. The position and angle adjustment within the plane range is achieved through the eccentric adjusting component, the position of the intramedullary rod is made to be matched with the tibia marrow cavity, the optimal coverage of the tibia platform prosthesis osteotomy plane is achieved, and the good stress of the tibia extension rod is achieved.

The utility model relates to the technical field of orthopedic medical instruments, and discloses a tibial prosthesis structure. Comprising a tibia prosthesis and a medullary cavity insertion section which are detachably connected, a first groove is formed in the outer side wall of the tibia prosthesis, a third groove is formed in the outer side wall of the medullary cavity insertion section, and the first groove and the third groove are sequentially communicated to form a long groove used for placing an implanted bone. The long groove is a bone grafting space extending in the length direction of the tibia prosthesis structure, the bone grafting material is contained in the long groove, on one hand, the bone grafting part can be prevented from protruding after an operation, and the occurrence rate of wound complications is reduced; on the other hand, healing of the patellar ligament and the bone grafting part is facilitated, the patellar ligament fracture risk is reduced, and the knee joint function of a patient is improved.

1. Name of the product of this design: Maxillofacial bone prosthesis (special shape‑2). 2. Application of this product design: for maxillofacial bone repair. 3. The key point of the design of this product lies in its shape. 4. The picture or photo that best illustrates the design points: three-dimensional picture.

A computer-executable method for selecting a femoral prosthesis (1) is carried out by acquiring a 3D model of a patient's femur at a pre-operative stage. A plurality of identification parameters identifying the structure of the femoral bone are measured / acquired on that model. These parameters are used to query a database with the aim of identifying within it the prosthesis (1) that best approximates the structure of the femur. Based on a correspondence between the measured parameters and the ones present within the database, the femoral prosthesis (1) having the highest number of matches is selected. Also proposed is an arthroplasty system comprising a plurality of prostheses (1) subdivided into families according to respective identification parameters enabling the identification of the specific prosthesis (1) that best satisfies and adapts to the needs and morphotype of the patient.

The invention relates to the field of medical instruments, in particular to a differentiated tibial plateau prosthesis system which comprises a plateau base, an inner side gasket, an outer side gasket and a central stand column. The platform base is provided with an inner side platform, a stand column platform and an outer side platform, and the stand column platform is located between the inner side platform and the outer side platform; the inner gasket is connected to the inner platform, the outer gasket is connected to the outer platform, and the central stand column is connected to the stand column platform; in the preset direction, the height of the outer side platform is larger than that of the inner side platform, and the inner side platform is flush with the stand column platform. The differentiated tibial plateau prosthesis system is matched with an artificial thighbone prosthesis for use, can effectively retain the bone mass of the proximal end of the tibia on the outer side of the knee joint, enables gaps between the inner side and the outer side of the knee joint which are originally large in difference to be balanced, reduces the requirement for releasing soft tissue on the inner side, avoids excessive releasing and stripping of the soft tissue of the knee joint, relieves the degree of postoperative pain, and improves the patient compliance. And the postoperative rehabilitation process is accelerated.

The invention relates to an ankle joint tibia prosthesis, an ankle joint prosthesis and a navigation system.The ankle joint tibia side prosthesis comprises a prosthesis body and a sliding part, the sliding part is arranged on the rear side of the prosthesis body, the position of the sliding part relative to the prosthesis body in the front-back direction of the prosthesis body is adjustable, and the sliding part is arranged on the back side of the prosthesis body. And the prosthesis main body and the sliding piece are in contact with a tibia osteotomy surface. The ankle joint tibia prosthesis can adapt to tibia anatomical structure differences of different patients, the covering effect of the ankle joint tibia prosthesis and the tibia osteotomy surface is good, the stability of the ankle joint tibia prosthesis after implantation is improved, and adverse reactions of postoperative patients are reduced.

The talus prosthesis is provided with an inner side face and an outer side face, the inner side face and the outer side face are arranged on the two sides of the median sagittal plane of the talus prosthesis respectively, and the inner side face and the outer side face are arranged in a projection orthogonal to the vertical direction of the talus prosthesis. The contour of at least one of the inner side face and the outer side face is a curve and protrudes in the direction away from the median sagittal plane. According to the talus prosthesis, the contact mode of the talus prosthesis and the inner side and the outer side of the tibia can be changed, direct rigid collision between the talus prosthesis and the tibia is avoided, the risks of abrasion, pain, inflammation and the like caused by collision between the talus prosthesis and the tibia are greatly reduced, the implanting stability of the talus prosthesis can be improved, and postoperative recovery of a patient is facilitated.

This invention discloses a method for coating tantalum on the surface of biomedical PEEK materials. The method includes the following steps: S1, PEEK pretreatment; S2, PEEK sample preparation: drying the pretreated PEEK wire in an oven and printing the PEEK sample using a high-temperature 3D printer; S3, using a Ta2O5 target as the evaporation source, employing DC magnetron sputtering technology, and adjusting the sputtering time and gas to coat the surface of the PEEK sample with tantalum of 250 ± 20 nm; S4, obtaining a tantalum coating on the PEEK surface after annealing. This invention provides a method for coating tantalum on the surface of biomedical PEEK materials, which can coat tantalum on the surface of PEEK without embedding the tantalum in the PEEK matrix. The obtained Ta-PEEK material has excellent osteoinductive properties and can be applied to implantable bone prostheses such as artificial temporomandibular joint substitutes.

An endoprosthesis intended to replace a resected portion of bone and joint. The endoprosthesis can be non-invasively, manually operated to lengthen a patient's limb both intraoperatively and postoperatively. It includes bone anchoring components for anchoring to a first and second long bone, a joint to replace the function of an orthopedic joint, and a purely mechanical lengthening mechanism which can be located and operated manually by an operator by pressing on skin of a patient without requiring a surgical incision. The axle for joint is the actuating mechanism that lengthens the implant. The endoprosthesis does not need or include any magnets, electric motors, electric current, application of heat or a fluid displacement (hydraulic) system.